It's 1953 and Sidney Chambers is vicar of Grantchester, a village just outside Cambridge, England. Sidney's is a quiet life. He tends to his flock, keeps up with his jazz collection, and does his best to contain his passion for beautiful heiress Amanda Kendall. But when one of his parishioners dies in suspicious circumstances, Sidney quickly finds that people confide things in a parish priest that they would never tell police.

It's the long hot summer of 1959 and wedding season is in full swing in the Cambridgeshire village of Grantchester. As the Reverend Will Davenport unites happy couples in holy matrimony, Detective Inspector Geordie Keating finds himself trying to repair his own marriage to estranged wife Cathy.

It's 1957, and it's as if the world of Grantchester has returned to an idyllic state, a metaphorical Garden of Eden. Will believes that everyone can get close to their own Eden through good works and a proactive attitude. But as Geordie knows, every Eden has its snakes. Will's faith will be tested as he and Geordie are reminded that there's darkness lurking in their corner of Cambridgeshire.